This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The C. elegans germ line forms a syncytium, making it possible for regulatory proteins to diffuse from one cell to another. We are quantifying diffusion properties using single-point fluorescent correlation spectroscopy and pair-correlation. Those quantitative data will be used to formulate mathematical models explaining how germline stem cells make a decision to self-renew or to differentiate.